I have utilized this plugin for a similar situation:
https://de.wordpress.org/plugins/ultimate-member/
Your users can register and create a profile. As the plugin comes with a lot of add-ons I’m not sure if there maybe is an add-on that solves your “attend” issue. If yes, problem solved. If not you could simply add a function which saves an array of gigs to the users profile.
I believe, that you’ll probably be better off using this than buddypress. Hope that helps.